Abstract: A computer system includes hardware for selectively disabling alteration of data residing on a mass storage device which is subject to remote access. In one embodiment, a hard disk drive is operated in a conventional manner including both read and write modes when the system is being operated in a non-secure mode of operation, such as when remote access is not allowed. In a secure mode of operation, a locally operated switch is used to disable writing to the hard disk drive to maintain data integrity on the drive. The system may also include first and second electrically isolated buses and corresponding processors. In this configuration, the hard disk drive may be selectively connected to the first bus and processor for the storage of data, or to the second bus and processor when in a secure mode to provide for read-only remote access to the information stored on the hard drive.